Aerosol valve



G. H. KLUN AEROSOL VALVE Oct. 15, 1968 Filed June 24, 1966 INVENTOR.GODFREY H. KLUN ATTORNEY WV M r l u 1 ll J o 4 2 4 United States PatentT 3,405,846 AEROSOL VALVE Godfrey H. Klnn, Parma, Ohio, assignor toUnion Carbide Corporation, a corporation of New York Filed June 24,1966, Ser. No. 560,162 3 Claims. (Cl. ZZZ-402.20)

ABSTRACT OF THE DISCLOSURE A resilient diaphragm is provided for apressurized metering aerosol valve which comprises a thin sleeve portionsurrounding the valve stem of said aerosol valve to cover a valve stemopening therein and control flow of aerosol formulation from themetering chamber through the valve stem opening. The sleeve-likeconfiguration of the diaphragm permits pressure within the meteringchamber to compress the diaphragm about the valve stem at the openingthereby enhancing sealing and preventing leakage.

This invention relates to aerosol containers, and more particularly tonovel and improved metering valves for aerosol containers.

Aerosol containers are known to be a very convenient means fordispensing fluids or solids suspended in a fluid stream. However, whenfinely divided solids either in a dry or in a slurry system aredispensed from such a container, presently available valves includingthose of the metering type tend to clog and inadvertantly limit or evencut off the fluidized stream of the dispensed material when such valvesare in an open position. This clogging is invariably caused by cakingand the tendency of the finely divided solids to agglomerate within thevalve body and subsequently obstruct and hinder proper valve action. Inaddition, solid particles tend to accumulate on the valve seat, valvespring, etc., after each use of the aerosol container and eventuallyprevent the complete closure of the valve means. This, of course,results in leakage of the propellent from the aerosol container andvitiates its further utility. Also, solid particles accumulating in thevalve increase the coeflicient of friction of the moving parts of thevalve and hinder its operation.

It is the principal object of the present invention to avoid theaforementioned difiiculties and to provide an aerosol valve of themetering type particularly well suited for use with aerosol containersdispensing finely-divided solid materials.

It is another object of the invention to provide an aerosol valve of themetering type which does not clog or stick during use and to provide anaerosol valve in which the biasing means is externally mounted and notin contact with the dispensed materials.

These and other objects and advantages of the present invention willreadily present themselves to the skilled artisan upon reference to theensuing specification and the drawing in which FIGURE 1 is a sectionalelevational view of the metering aerosol valve of the present invention,and FIGURE 2 is a sectional view taken along the line 22 of FIGURE 1 andshowing the lands of the valve in greater detail.

The objects of the present invention are achieved by a metering aerosolvalve assembly the principal feature of which is a valve body having acentral metering chamber communicating with an eductor tube or dip tubeextending into a suitable aerosol container. The valve body isconventionally sealed to the top closure and suitably supports therein acentrally disposed hollow valve stem by means of a steel support washerand a resilient diaphragm. The valve stem is biased upwardly so as tomaintain upper slide valve means in a closed position by means of anexternal compression spring disposed about the 3,405,846 Patented Oct.15, 1968 valve stem between the steel support member and a flangedportion of the valve stem. A spring housing positioned about thecompression spring acts as a stop for the valve stem. At the base of thevalve body is a comically-shaped valve seat which communicates with theeductor tube and with the closed end of the hollow valve stem. The upperslide valve means comprises a transverse inlet opening whichcommunicates with the metering chamber to direct the metered charge toan axial outlet opening in the valve stem when said stem is depressedand biased downwardly to the open position.

Since the instant metering aerosol valve contemplates the use of aresilient diaphragm having a central bore through which the valve stemis slidably disposed, valve operations can be further enhanced bydecreasing the coefiicient of friction of the moving parts within thevalve assembly. An additional benefit can be gained if the valve stem,selected portions thereof, or the stationary bearing surfaces of thevalve assembly are coated with a permanent resilient coating of ahalohydrocarbon polymer. Typical illustrative halohydrocarbon polymersare homopolymers of tetrafluoroethylene, copolymers oftetrafluoroethylene and hexafiuoropropylene, and the like.

The coelficient of friction between the moving parts of the instantvalve can be conveniently reduced by applying thereto a lubricant, whichis relatively non-volatile under the normal service conditions of theaerosol valve and which is compatible with the materials of constructionemployed and with the components of the aerosol system. The lubricantcan be applied also over the coated portions of the valve stem. Typicalof such lubricants are hydrocarbon oils and greases, silicon oils andgreases, and the like. Also, contemplated are the suspensions in theaforementioned oils and greases of solid lubricants such as graphite,molybdenum disulfide, boron nitride, powdered tetrafluoroethylenepolymers, and the like.

Illustrative hydrocarbon base lubricants are mineral oil, petroleumjelly, polyglycols, and the like.

Illustrative silicon oils and greases are organic-siloxane fluidpolymers with or without a thickening agent such as reactive silica,silica admixed with reactive boric oxide, soaps, and the like.

In FIGURES 1 and 2 of the drawing, there is shown a valve body orhousing 10, and a resilient flanged diaphragm 12 which seals off theupper end of the housing 10 and together with the housing 10 defines ametering chamber 14. Suitable supporting means such as rigid washer 16overlies the diaphragm 12 and serves to support suitable biasing means,such as compression spring 18, the latter of which is used to maintainthe valve assembly in a closed position.

The valve stem 20 may be of plastic and is suitably tubular in form andclosed at its lower hemisphericallyshaped end 21 (hereinafter describedin greater detail). The stem 20 is mounted in the housing 10 and isprovided with a longitudinal conduit 22 and an upper lateral valve stemopening 24. If desired, the lower portion of the valve stem 20 below theopening 24 may be solid. As best shown in FIGURE 2, a plurality of lands15 guide and center the valve stem 20 within the valve housing 10. Threelands are suitable in the practice of the invention although four landsare illustrated and described herein. In the closed position of themetering valve of the invention, the upper lateral opening 24 is locatedadjacent to and covered by a depending sleeve portion 25 of thediaphragm 12. The central portion of the valve stem 20 extends throughand is slidable in the central bore 26 of the diaphragm 12 and the valvestem is sufficiently long so as to project beyond the top of an aerosolcontainer (not shown) so as to accept an actuator button 28.

Near the upper portion 30 of the valve stem 20 is a suitableprotuberance or annular ridge 32 which functions 3 as a shoulder for thespring 18 and as a limit stop for the valve stem 20. If desired, theoutside surface of the valve stem 20 may be coated with ahalohydrocarbon polymer coating which provides a resilient matingsurface with the diaphragm 12. The lower hemisphen'cally-shaped valvemeans 21 of the valve stem 20 is in proximity to a lower tapered valvestem seat 34 provided in the bottom portion of the valve housing 10. Thevalve means 21 serves to seal off the tapered opening 36 in valvehousing 10 when the actuator button 28 is depressed and the meteringvalve of the invention is in the open position and expelling the meteredcharge residing in the metering chamber 14. The seat 34 is noted to haveextending tip portion 45 which is urged into sealing engagement withsaid lower valve means 21 'by the internal gas pressure of said aerosolcontainer. This same gas pressure is noted to aid in sealing said uppervalve stem opening 24 with the depending sleeve portion 25 of saiddiaphragm 12 (see arrows in FIG- URE l).

The compression spring 18 is situated externally about the valve stem 20between the rigid washer 16 and the annular ridge 32 so as to urge thebottom portion 21 of the valve stem 20 away from being in sealingengagement with the conical opening 36 of the valve stem seat 34. Thevalve assembly of the invention is held in place within an aerosolcontainer by means of a conventional top cover or closure 37. The flangeportion 39 and the crimp 41 of the closure 37 provide the means by whichthe valve assembly is held together and fixedly disposed and suspendedwithin an aerosol container (not shown).

A conventional eductor tube 38 extends within a standard type aerosolcontainer and is mounted to the lower portion of the valve housing 10 soas to communicate with the chamber 14 thereof. Care should be taken thatthe passageway of the eductor tube is not too close to the bottomportion 21 of the valve stem 20 so as to avoid compacting of loosepowder against the passageway of the eductor tube 38 thereby pluggingit. The proper spacing can be readily ascertained by one of ordinaryskill in the art.

The actuator button 28 has a longitudinal passage 40 provided with adischarge orifice 42 the effective diameter of which is greater thanthat of the stem opening 24 to prevent clogging. The longitudinal pasage40 communicates with the longitudinal conduit 22 of the valve stem 20 bymeans of the axial opening 43 at the upper end of the valve stem 20.When the actuator button 28 is depressed the valve stem 20 is movedlongitudinally to compress against the spring 18 and from a normalsealing or closed position to an open or discharge position. The open ordischarge position is reached when the longitudinal conduit 22communicates with the chamber 14 of the valve housing 10 via the uppervalve stem opening 24. Upon release of pressure on the actuator button28 the spring 18 returns and closes off the upper valve stem opening 24of the valve stem 20 and opens the lower valve means 21 thus allowingthe metering chamber 14 to be filled for the next metered charge.

The location of the upper valve stem opening 24 is critical in that ismust be such that when the valve stem 20 is moved longitudinally toadischarge position, the upper opening 24 is moved away from itssealingrelationship with'the diaphragm 12 and into communication withthe metering chamber 14. At the same time, the lower bottom valve 21 ofthe valve stem 20 seals off the metering chamber 14 whereby enablingonly a predetermined metered quantity of aerosol formulation within thecavity 14 to be expelled from the aerosol container. The tapered opening36 is noted to be completely sealed before the opening 24 enters thechamber 14. Similarly, when the actuator button 28 is released, theopening 24 must leave the chamber 14 before the same is opened to theeductor tube 38 and the internal pressure of the aerosol containerwhich, of course, automatically fills the metering chamber 14 every timethe valve assembly is in the normally closed or sealing position.

, i l In the metering valve of the invention, the chamber 14 is filledby the pressurized aerosol formulation with the material to be dispensedwhen the valve stem 20 is not depressed and the lower valve 21 is in anopen position while the upper valve stem opening 24 is in the normallyclosed or sealing position. When the valve stem 20 is subsequently movedto the discharge position, the material contained in the chamber 14 isdispensed through the discharge orifice 42 by means of opening 24,longitudinal conduit 22 and opening 43. Of course, the dosage to bedispensed is controlled by the capacity or volume of the chamber 14. Itshould be noted that the compression spring 18 is externally mounted anddoes not come into contact with the material to be dispensed so thatconsequently it cannot be clogged and will essentially be jam-proof.Tests have shown that when the bias means is positioned where it will bein direct contact with the material to be dispensed, repeated use ofsuch a valve will cause the bias means to become clogged and henceinefiective. It should also be noted that the gas pressure in thecontainer and in the metered cavity aids in respectively holding theextending tip portion 45 of said lower tapered valve seal 34 in sealingengagement with the lower valve means 21 of the valve stem 20, and inholding the depending sleeve portion 25 of said diaphragm 12. in sealingengagement with said upper valve stem opening 24.

The foregoing discussion is intended to be illustrative. Othermodifications of structure and rearrangement of the parts can beresorted to without a departure from the spirit and scope of the presentinvention.

What is claimed is:

1. In a metering aerosol valve for a pressurized aerosol containerincluding a housing defining a metering chamber containing a pressurizedpredetermined quantity of aerosol formulation to be dispensed, lowervalve means defined by said housing through which aerosol formulationmay flow from said container to said metering chamber, a valve stemextending into said housing and defining internally thereof a passagewayfor dispensing aerosol formulation from said metering chamber, valvestem opening means defined by said valve stem between said passagewayand said metering chamber, spring means mounted exterio rly of saidvalve stem biasing said stem to a closed-valve position and defiectableto permit displacement of said stem to an open-valve position, closuremeans surrounding said valve stem blocking flow through said valve stemopening means when said stem is in said closed-valve position andpermitting exposure of said valve stem opening means to the aerosolformulation in said metering chamber when said stern is in saidopenvalve position, and means on said valve stem blocking flow throughsaid lower valve means when said stem is in said open-valve position,the improvement in combination therewith wherein said closure meanscomprises a resilient diaphragm having a relatively thin sleeve portionsnugly extending over a portion of the exterior of said valve stem whichis exposed to pressure within said metering chamber, said sleeve portionbeing compressed by said pressure about said valve stem therebyenhancing the sealing engagement of said diaphragm over said valve stemopening means. i

2. In a metering aerosol valve according to claim 1 the improvement incombination therewith wherein said lower valve means comprise aconically shaped opening defined by a conically shaped lip portionextending from said housing, with the end of said valve stem moving intosaid opening when in the open-valve position, said end of said sternbeing shaped to block aerosol formulation flow through said valve means,said valve stem end being completely disengaged and out of contact withsaid conically shaped lip portion when in the closed-valve positionthereby penmitting com-pletely free flow of aerosol formulationtherethrough.

3. A metering aerosol valve according 'to claim 2 wherein said conicallyshaped lip portion is configured to be compressed against said valvestem when in the open-valve positon by pressure within said aerosolcontainer thereby enhancing the sealing engagement therebetween.

References Cited UNITED STATES PATENTS 2,822,960 2/1958 Lengel 222402.24

6 3,128,924 4/ 1964 Gorman 222402.2 3,178,078 4/ 1965 Wittke 222402.2

FOREIGN PATENTS 1,264,367 5/1961 France.

ROBERT B. REEVES, Primary Examiner.

F. R. HANDREN, Assistant Examiner.

